Follicles in the ovary undergo a continuous process of growth and regression; only a small minority actually proceed to ovulation. Substantial evidence suggests that atresia oocurs by the process of apoptosis, or programmed cell death. This project is studying the role of two genes, bcll-2 and the Fas antigen, which have been demosntrated to be intimately involved in apoptosis in other systems, inducing and supressing the process, respectively. The experiments require the long term examination of living rat and human granulosa cells by time-lapse video LM, followed by fixation and immunofluorescence or serial section HVEM. An understanding of follicular degeneration is essential to allow development of improved methods of fertility control, treatment of infertility and enhancement of fertility. There is intense interest in programmed cell death because of its involvement in a wide variety of normal developmental processes as well as its relevance to the development of cancers. The ovary provides an excellent model for the study of programmed cell death. The results of this study were published this year in Biology of Reproduciton.